The present invention relates to a set-down box of a labelling machine, including:
a conveyor means used to place the labels over the articles to be labelled;
a vertically displaceable pressing means used to press the labels on the articles to be labelled;
a means used to vertically displace the pressing means;
a motor with clockwise and anti-clockwise rotation; and
a driving means transmitting the driving power of the motor to the conveyor means and to the means used to vertically displace the pressing means;
wherein the means used to vertically displace the pressing means has a free-wheel in one direction of rotation of the motor.
Packaged articles, e.g. foods, are provided with labels nowadays. As a rule, such labels are unrolled from a dispenser, placed over the articles to be labelled, and then pressed thereagainst so as to firmly adhere thereon. The currently available set-down boxes have several driving units and are highly complex and large in design.
It was therefore the object to provide a set-down box which would not involve the drawbacks of prior art and would be simple to produce.
According to the invention, said object is accomplished by means of a set-down box of a labelling machine, including:
a conveyor means used to place the labels over the articles to be labelled;
a vertically displaceable pressing means used to press the labels on the articles to be labelled;
a means used to vertically displace the pressing means;
a motor with clockwise and anti-clockwise rotation; and
a driving means transmitting the driving power of the motor to the conveyor means and to the means used to vertically displace the pressing means;
wherein the means used to vertically displace the pressing means has a free-wheel in one direction of rotation of the motor.
The driving means for the conveyor means and for the means used to vertically displace the pressing means preferably is free of slip. It is particularly preferred that the driving means be a toothed belt or a chain.
The pressing means can both be lowered and lifted by the means for vertically displacing the pressing means. In a preferred embodiment of the present invention, however, the pressing means has a return spring pressing the pressing means from a deflected end position back into the starting position. In a preferred embodiment, the pressing means has a vertical guide. This guide preferably is comprised of one or more spherical shells.
The conveyor means is used to place the labels over the articles to be labelled. To this end, the conveyor means either must have means making the labels adhere to the conveyor means, or, an air stream and/or a vacuum must be generated holding the labels against the conveyor means by pressure and/or suction. The conveyor means is driven by a driving means. In a preferred embodiment, the conveyor means consists of several conveyor belts being from 2 to 10 mm in width and essentially extending across the entire width of the respective packaging machine. The conveyor belts preferably are spaced apart by 2 to 10 mm.
Any means is suitable as pressing means that allows pressing the labels on the articles to be labelled, so that the adhesive layer located beneath the labels can make better contact with the articles. The pressing means preferably is a pressing plate as described below.
In a preferred embodiment, the means used to vertically displace the pressing means is a lever arm, a cam rotatable at its one end about an axis, which lever arm/cam is driven by said driving means and has a free-wheel in one moving direction of the driving means.
In particular, a stepper motor is suitable as motor, which preferably is computer-controlled.
The set-down box of the invention is advantageous in that its production is easy and convenient and that it has only one driving unit. It is efficient in terms of energy, and no pressurized air is required to press on the labels. Not more than one unit has to be controlled by a control.
The present invention is also directed to a pressing plate having a plurality of plungers displaceable relative to the pressing plate. The plungers preferably are sprung in a bearing, preferably in a shell. Resilience can also be provided using helical springs or disc springs, or compressible media such as air.
The pressing plate of the invention is advantageous in that unevenness in the contour of the articles to be labelled can be compensated very well. The pressing plate according to the invention can be produced in an easy and convenient fashion.
The present invention is also directed to a method of attaching labels on articles to be labelled using the set-down box of the invention, said method consisting of a succession of the following steps:
1. positioning the labels over the articles to be labelled using the motor-driven conveyor means;
2. reversing the moving direction of the driving means until said means has displaced the pressing means from its upper starting position to its lower end position, with simultaneous pressing of the labels on the articles to be labelled, and
3. re-reversing the moving direction of the driving means to return the means used to vertically displace the pressing means and thus, the pressing means to its starting position.
In a preferred embodiment of the method according to the invention, the conveyor means is stopped between the processing steps 1. and 2. and/or 2. and 3. for 0 to 1 second.
The method according to the invention is advantageous in that its implementation is easy and convenient and that only one driving unit is required. The method is efficient in terms of energy, and no pressurized air must be provided to press on the labels. Not more than one unit has to be controlled by a control.